Douglas Bag Exam

Question 1

What is the equipment involved?

Answer 1

\+ Douglas bag rack 4 bad
\+ Mouth piece 
\+ 3 way valve
\+ Blue paper
\+ Nose clip
\+ Stop watch - to time the collection period
\+ Breathing tube
\+ Monark cycle ergometer 
\+ Heart rate monitor 
\+ RPE scale - (Rating of perceived exertion) - Borg scale - 6-20
\+ Vacuum pump and extraction tube to empty the douglas bag before use
\+ Environmental stations 
\+ Stadiometer - height
\+ Body mass scales - weight 
\+ Gas analysis station

Question 2

Pre testing prep:

Answer 2

\+ Explain whats involved
\+ Consent
\+ PARQ
\+ Witness Sign PARQ
\+ Measurements: Participants- Weight, Height, BMI. 
Room - Temp, Pressure, Humidity

Question 3

What you are testing and why?

Answer 3

Measures gas exchange and substrate usage, in submaximal range.

By measuring the volume of air we breathe in and out in 1 min, and the composition of oxygen and carbon dioxide in that breath sample we can determine what substrates are being utilised for energy provision – this is called indirect calorimetry.

Question 4

Define submaximal exercise.

Answer 4

Submaximal performance testing is a way of estimating either VO2 max or “aerobic fitness” in sports medicine. The test protocols do not reach the maximum of the respiratory and cardiovascular systems. Submaximal tests are used because maximal tests can be dangerous in individuals who are not considered normal healthy subjects and for elite athletes maximal tests would disrupt training load balance.

Question 5

How can you determine Submax in a particpant?

Answer 5

220-age

50-70% Heart rate reserve

Question 6

Whats the basic exercise protocol and gas sampling?

Answer 6

Stage 1: Start exercise 0-4 mins. 4-5 mins collect air. 5th minute add more weight.

Stage 2: exercise 5-9. 9-10 collect air. Finish test.

Question 7

How do you calibrate the gas machine?

Answer 7

+ Switch on the system to warm up

+ Connect gas line and open the cylinder and regulator value 1000cc/min

+ Set O2 low and entre calibration - 2 mins to o2 0.00%

+ Repeat co2 low until stabilised

+ Connect gas line and open the cylinder and regulator value 1000cc/min

+ High span gas o2 high - gas 2 mins target 16.08%

+ Co2 high - 5.03%

+ Sample ambient air 2mins - make note o2 and co2 values to calculate vo2 and vco2

+ 02 = around 20%

+Co2 = around 0.08%

Question 8

How do you open and close the douglas bag valve?

Answer 8

90 degrees clockwise to open and turn the valve 90 degrees anti-clockwise to close

Question 9

What are normative values for a male?

Answer 9

Stage 1 of exercise: 120W
1.5kg x 80 rpm x 6 = 120W

Stage 2 of exercise: 160W
2.0 kg x 80 rpm x 6 = 160W

Question 10

What are normative values for a female?

Answer 10

Stage 1 of exercise: 80 W
1.0kg x 80 rpm x 6 = 80W

Stage 2 of exercise: 120W
1.5kg x 80rpm x 6 = 120W

Question 11

Whats the name of the standard table showing the caloric value of a litre of oxygen when used to oxidise mixtures of carbohydrate and fat?

Answer 11

zuntz table:

RER value of 1.00 = metabolising carbohydrate

RER value of 0.7 = metabolising fat

Question 12

How do you work out work?

Answer 12

Force (kg) × Distance (meters/min) = Work (kgm/min)

Question 13

What is cadence?

Answer 13

Revolutions per minute or RPM

Question 14

What is the energy system involved?

Answer 14

Oxidative phosphorylation – glucose, free fatty acids, protein.